The present invention relates to a binding machine for the application of a strip of flexible material around the outline of thin articles, particularly for edging parts for boots and shoes, such as soles or insoles, with a strip of leather or similar material.
More precisely, the invention relates to a binding machine of the type that comprises a hollow shaft oscillating about its axis, a pressure and transportation group, driven by said shaft, said pressure and transportation group comprising a hammer shaped part and an anvil shaped part, a first rod in the hollow shaft coaxial therewith driven reciprocably longitudinally to control pressing of the strip in a folded condition, and a second rod parallel to said hollow shaft driven reciprocably longitudinally, a fork actuated by said second rod to fold the strip partly above and partly below an edge of a thin article before the pressing operation.
The known machines of this type have complex, costly, structures requiring special actuating units with which to operate the various component parts.
It is known a folding machine wherein the folding is got by means of a horizontal bar pivoted to a vertical rod having an end fastened to a driving rod operated in a reciprocating way according to an axial direction. Said bar is rested against an end of an arm turningly mounted upon a central pin and having, on the other end, a tooth which cooperates with a corresponding tooth of a clamp. Moreover, elastic means are provided to maintain in a horizontal position said bar, while, to get a correct folding of the edge a flexible material, it is necessary on the working plan the presence of an abutment having a curved surface with upwards concavity.
It is furthermore known a binding machine, wherein the working tools, which are the alternatively movable fork to fold the strip partly above and partly below the outline of the article and the pressure and transportation group to press the strip on the article and to remove the worked article, as driven by eccentrics mounted upon a shaft placed beneath the working tools. A system of leverages and rods, complexly assembled among each others, provide to transfer the movement from the driving shaft to the working tools.
The hereinbefore specified complicated driving mechanisms, besides negatively influencing the reliability and the manufacturing and maintenance costs of the binding machine too, need to be assembled into a box shaped body to avoid that the lubrication of the mechanisms causes sprays of lubricant around the working area. This box shaped body is placed upon the working plan of the binding machine causing encumbrance which limits considerably the available space to handle the piece to be worked easily and to make the binding operation difficult and imprecise. This happens particularly when soles and cork soles of women shoes are to be edged, because these ones are extremely shaped.